the thing is bubble wrap can make a plant sweat if no air circulating, not sure if it will be ok or not, fleece is better cause air can still get in

I know how you feel, I have lost five this winter and that is how they looked. I would chop the spongy bits off and just keep your fingers crossed but I dont hold much hope. My oldest one was about 10 years old and I thought nothing could of killed it because it was even in a shady place. Sorry.

Thank you all for your help... we are so upset at the moment, but we have also decided to try and save it.

If we cut it down by a foot and remove the bad part of the trunk can it recover?

apparently if you cut the top off it may well regrow with multi heads so worth a try ;o) also read you seal the cut with arbrex , guessing it may or maynot work, but it must be worth a go